Just bought an 08 Mazda 6 and have hit a roadblock adding Sirius. I have looked all over and keep finding the OEM tuner for about $300. I would prefer to buy a universal tuner and get an interface to work with the factory stereo. I can get a universal tuner for $80 but have not found an interface for it. Seems like there is one for every make except Mazda. Can anyone help me out?